(cba:news) august stars
jop at astro.columbia.edu
Thu Jul 30 09:01:50 EDT 2020
1. In recent years we've been accumulating a lot of data on "old novae",
including some that are not so old, plus otherl which are related to old
novae (which could be suspects from the pre-temescopic age, or which
probably burn hydrogen stably rather than explosively). It's time to
bring some of these studies to print... and therefore to get a good
final season, the better to nail down - typically - the orbital waveform
and period change.
These are NR TrA, V4743 Sgr, Nova Sco 1437, V Sge (bright!), V617 Sgr,
and QR And. All new objects for this season, but friends of ours from
past years. None are *fast* variables, so you can just pick a time
resolution you're comfortable with. Howeve, since the period of
interest is ORBITAL, the observation should be long (at least 3 hours)
V1494 Aql and V1974 Cyg are entitled to be on this list. But V1494 has
been well taken care of this year, and the signal in V1974 is hard to
spot. So I'm taking them off.
2. Intermediate polars (DQ Her stars). Right up our alley to measure
period change, since we have baselines of 5-20 years. The ones needing
just occasional observation are FQ Aqr and AO Psc. V1223 is more
interesting since it has been much more active this year, and a
still-unsettled question is the connection between brightness and period
change. It will take some patience to settle this.
Then there are IPs that we have observed frequentlybut never quite
published our results. A good season on these will push us to
completion! These are V515 And, V1033 Cas, V2069 Cyg*, V2306 Cyg*, and
V598 Peg. The asterisk here means "we have a lot this year, but should
take it to the end of the observing season, in order to secure a correct
cycle count from one year to the next (or the previous).".
3. The asynchronous polars. The good ones this season are CD Ind and
V1432 Aql. Need longish runs.
4. It's usually a good idea to find a good target, well placed in the
sky, and stick with it. But that's less true for the IPs, where early-
and late-season observations can be critical in specifically long-term
I have at least the next semester off from teaching, and expect to
bring a number of these studies to completion!
p.s. don't overlook N Sco 1437 - A really spectacular light curve!
haven't made its acquaintance, A spectacular light curve
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